Method of impregnating wood.



RICHARDYLAMBWOVF NEW YORK, N..Y.

Mn'rHon or rmrnneuarmo woon.

No Drawing To all whom it may concern:

. Be it known that I, RICHARD LAMB, a citizen-of the United States,residing at New York city, State of New York, have invented certain newand useful Improvements in Methods of Impregnating Wood; and I do herebydeclare the followin to be a full, clear, and exact description 0 theinvention, such as will enable others skilled in the art to which itappertains to make and use the same.

My invention relates to the impregnating of porous materials-such asfelt, wood, etc. The methods heretofore used are, first the Bethelprocess: fillingthe pores, cells or hollow spaces with the impregnating,liquid to an unnecessary extent; second, the Lowry process: aftersaturation of the wood under pressure, subjecting the wood to the actionof a vacuum, which only imperfectly removes the superfluous impregnatingmaterial; third, the Rue'ping process: the wood is subjected to acompressed gas or air pressure, and while maintaining the pressure,injecting the impregnating liquid at a still higher pressure, which whencut oil permits the compressed gas or air, previously inserted, to ejectthe surplus impregnating ma- I terial.

In comparison with-previous methods the present invention hasadvantages. It is an improvement over the Bethel process in that itprovides a cheap and efficient method of ejecting the surplusimpregnating material from thewood. It is an improvement over the Lowryprocess in that a vacuum alone is.

not an etficient medium to withdraw thesurplus impregnating material. ItIs an 1mprovement over the Ruepingprocess in that.

it is possible to use the Rueping process without sterilizing the woodwith steam, a step recognized in the art as very advantageous in allcases, and absolutely necessary when treating green wood. While steamcan be used as a separate and preliminary treatment in the Ruepingprocess it is declared by the inventor that the preliminary treatment ofthe material by steam is not necessary, but that in certain cases it canalso be made use of. It is not named as a step in the process in any ofthe claims. In I the Rueping process it is necessary to provide andmaintain a gas or air compressor. My invention sterilizes the wood andrequires no compressor.

As one example of the working of my in- Specification of Letters Patent."Patnted J an 13, 1916 Application filed February 17, 1915. Serial No.8,896.

7 destroy the pressure of the steam. After pumping creosote oil into thehermetically sealed cylinder in which the wood has been placed, withdrawthe oil. The steam pressure in the wood will eject the oil from the Woodto an extent determinable by experiment,varying with different woods.Pressure above given can be varied as conditions may direct. After thepressure is relieved, the usual vacuum can be applied to assist .indraining the wood of surplusimpregnating material.

The effect of my invention can be explained as follows: The steampressure opens .the pores and sterilizes the wood. While the poresare-still open and the steam still under pressure, the impregnatingmaterial, which in many cases will be creosote oil, is injected under agreater pressure than the steam pressure, and at a temperature as highas that of the steam. The impregnating material will be given a pressuresuflicient to thoroughly impregnate the wood, coating by results isnecessary to properly protect the wood, thus saving for fiirther use thesurplus impregnating material ejected.

I claim 1. The method of impregnating wood andother porous materials,which consists in placing the material to be treated in a hermeticallysealed cylinder, and subjecting same tosteam pressure, then under agreater pressure, and with as high adegree of heat injecting theimpregnating material into the material to be treated, then withdrawingthe impregnating material from the cylinder, when the steam pressurewill eject the surplus impregnating material from the material treatedsubstantially as described.

2. The method of impregnating wood and other porous material, whichconsists in placing the material to be treated in a hermetically sealedcylinder and-subjeeting'same to steam pressure, then under a greaterpressure and with as high a degree of heat injecting the impregnatingmaterial into the material to be treated, then withdrawing theimpregnating material from the cylinder when the steam pressure willeject the surplus impregnating material from the mate rial treated, thenproducing a 'vacuum in the cylinder to assist in ejecting the surplusimpregnating material substantially as described.

